Gas hydraulic spring for crushing apparatus



A ril 25, 1967 Original Filed Aug. 51, 1962 ni'n 7 gal/ 6/ 1 aa FIG 3INVENTOR 2 HAR LD .PoLL/TZ ATTORNEY United States Patent 0 11 Claims.(Cl. 241211) The present invention concerns crushers, of the gymtory andcone types, for instance, 'which incorporate spaced crushing membersbetween which material is crushed by movement of the members withrespect to each other, and particularly relates to means for maintainingand adjusting the spacing between the members and for permitting itresiliently to increase should the design load of the crusher beexceeded.

This application is a division of copending application Serial No.220,697, filed August 31, 1962, now abandoned.

In the case of crushers of the .gyratory type, adjustment of thecrushing mantle relative to the bowl is usually achieved by supportingthe lower end of the mantle mainshaft upon a hydraulic jack whichpermits the mantle to be raised toward or lowered away from the bowl. Inorder to accommodate overloads, such as tramp iron, for instance, thehydraulic circuit of the jack incorporates an accumulator pressurizedwith gas. hydraulic fluid in the jack becomes greater than that of thegas, owing to the introduction of tramp iron into the crusher, fluid isforced from the jack into the accumulator, thus permitting the mantle tolower in order to increase the space between it and the bowl until thetramp iron is discharged. In the case of crushers of the cone type, onthe other hand, adjustment of the cone relative to the bowl is usuallyaccomplished by movement of the bowl itself. Overloads are absorbed bysuitably positioned coil spring assemblies compressed between the bowland the crusher frame, thus permitting the bowl resiliently to riserelative to the cone upon the introduction of tramp iron, for instance.

The use of a hydraulic jack type of suspension in the case of a gyratorycrusher for both adjustment and overload protection involves substantialexcess equipment besides the jack itself, including a fluid reservoir,an accumulator, and all the necessary connecting piping. Furthermore,the crusher cannot readily be disassembled, or the jack readilyreplaced, without substantial time being required to disconnect thehydraulic reservoir and accumulator and to drain the jack. Uponreassembly of the crusher, the jack must be refilled with fluid andreconnected into the hydraulic system. Even a simple adjustment of thespacing between the mantle and bowl requires pumping fluid in or out ofthe jack. In the case of a cone crusher, while adjustment of the spacingbetween the cone and the bowl is usually achieved by means other thanthat provided to accommodate overloads, nevertheless much time andeflort is necessarily involved in backing off and/ or turning up thenuts compressing the coil spring overload assemblies around the bowl inorder to replace or adjust same. Consequently, crusher shut down timemay be lengthy in the event of such replacement or adjustment.

It is toward elmination of the disadvantages outlined. above that thepresent invention is directed. For this purpose, the hydraulic jack ofthe gyratory type crusher and the coil spring assemblies of the conetype, as the case may be, are replaced with one or more self-containedgas hydraulic springs. Each of the latter incorporates essentially ahydraulic cylinder pressurized with a suit- When pressure on the ablegas which in turn exerts its force upon a main piston and a piston rod.An additional or floating piston may also be incorporated in thecylinder in order to provide for better lubrication and sealing. As:applied to a gyratory type crusher, for instance, one or more suchsprings, each having a fixed, maximum over-all length when uncompressedand compressible to a lesser length, are simply inserted in place of theusual hydraulic jack so that forces between the crushing bowl and mantleare transmitted by the lower end of the latters shaft to the cylinderand piston rod axially thereof. Simple snub bolts, operative forinstance between the end of the assembly remote from the mantles mainshaft and the end of the hub of the latter, permit easy and rapidraising or lowering of the mantle to adjust the space between it and thebowl, as well as a means of removing end play between the hydraulicspring assembly and the mantles main shaft. As used herein, theexpression design load of the crusher is intended to refer to the loadabove which damage to the crusher begins to be likely. The design loadis thus greater than what may be called the crushing or working loadwhich is imposed upon the crusher during its regular operation. Thecylinder is pressured therefore so that it exerts a force on the pistonand rod in excess of the crushing or working load, preferably, in fact,equal to the design load of the crusher. Accordingly, when an overloadwould otherwise occur, that is, when the design load of the crusherwould be exceeded, the gas in the cylinder is simply compressed by axialmovement of the mantle until the tramp iron or other extraneous matterhas been discharged, whereupon the mantle is returned to its originalspacing from the bowl. Since the assembly itself exerts no pressure uponthe mantles shaft until it is compressed, it is easily disengaged forremoval as a self-contained unit, simply by backing off the snub bolts.

Essentially the same unit can be applied to a cone crusher. In that caseseveral hydraulic springs of the present invention are simply insertedin place of the usual coil spring assemblies between the bowl and theframe and also pressurized to exert a total force equal to the designload of the crusher. Snub bolts are also provided which can be turned upagainst one end of each spring, as in the case of the gyratory crusher.As before, each unit is pressurized so that the total of the forcesexerted by all such springs is equal to the design load of the crusher.Accordingly, should an overload occur, the gas in the cylinders iscompressed, allowing the spacing between the cone and bowl resilientlyto increase and then to return to its original setting after dischargeof the extraneous matter. The use of these springs in cone crushers alsoeliminates the need for any additional overload safety devices, overloadprotection being achieved instead, simply by providing a suflicientstroke for the piston of each hydraulic spring.

In addition, in the case of the cone crusher, the laborious and lengthyprocess of turning up or undoing several screw nuts is unnecessary inorder to achieve the necessary spring pressure. Instead, such pressureis instantly available as son as the snub bolts are turned up to capturethe hydraulic springs firmly between the frame and bowl. Note also thatthe snub bolts need not be turned up to compress the gas, but onlyenough to remove any play between the ends of each spring and the seatsagainst which they abut. Each hydraulic spring can be simply and easilyinstalled or removed inasumch as it is not only wholly selfcontained butalso has a fixed, maximum length; as in the case of the application to agyratory crusher, it is not necessary, therefore, to discharge thecylinder in order to release the spring from the crusher.

Accordingly, the primary object of the present invention is theprovision of a self-contained gas hydraulic spring for crushers of thetypes described which permits both the spacing between the crushingmembers to be easily and quickly adjusted and an overload to be safelyabsorbed without need of crusher shutdown.

Another object of the present invention is to provide crushers of thetypes described with self-contained gas hydraulic springs interposed toresist increase in the spacing between the crushing members, each springincorporating a cylinder filled with gas to a pressure so that the totalforce exerted by all such cylinders is equal to the design load of thecrusher.

A further object of the present invention is the provision of crushersof the kinds described with gas hydraulic springs interposed to resistincrease in the spacing between the crushing members, each springincorporating a piston, a piston rod and a cylinder filled with gas to apressure so that the total force exerted upon all the piston rods isequal to the design load of the crusher, each spring beingself-contained and having a fixed maximum length.

An additional object of the present invention is to provide aself-contained gas hydraulic spring, preferably of fixed maximum length,for crushe-rs of the kinds described, each unit incorporating acylinder, a main piston and piston rod and a floating piston, thecylinder being capable of being pressurized with gas between one endthereof and the free piston and of being filled with a non-compressiblelubricating fluid between the main and floating pistons.

Other and further objects, features and advantages of the presentinvention will be apparent from the preferred form thereof hereafterdescribed, read in conjunction with the following drawings, in which:

FIGURE 1 is a side view, partly in section, through the axis of one ofthe gas hydraulic springs utilized in the crushers illustrated inFIGURES 2 and 3;

FIGURE 2 is an elevational view, partly in section of a typical gyratorytype crusher illustrating the application thereto of the hydraulicspring illustrated in FIGURE 1; and

FIGURE 3 is an elevational view, partly in section, of a typical conetype crusher illustrating the application thereto of the hydraulicspring shown in FIGURE 1.

Each gas hydraulic spring 30 illustrated in FIGURE 1 incorporates ahollow cylinder 31, closed at one end by end cap 32, and provided with amain piston 33 slidable therein having a piston rod 34 integraltherewith extending axially therefrom to beyond the other end ofcylinder 31, an O ring 35 providing sealing between cylinder 31 andpiston 33. The length of cylinder 31 and the stroke of piston 34 will,of course, depend primarily upon the amount of movement required inorder for the crusher safely to absorb any possible overload. Theremaining end of cylinder 31 is internally threaded to receive anexternally threaded end plug 36 bored axially to slidably receive pistonrod 34 therethrough. An annular wiper type seal 37 between rod 34 andplug 36 is provided at the outer end of the bore through the latter. Endplug 36 is locked in place by means of a threaded retaining ring 38turned up tightly thereagainst. Piston 33 and rod 34 are bored axiallyto provide a passage 39, communicating with the interior of cylinder 31,its outer end being counterbored in turn to receive a removable plug 40threaded therein well below the outer end of rod 34. A second orfloating piston 41 is also provided in cylinder 31 and is slidabletherein between end cap 32 and piston 33. Piston 41 has its oppositeends 42, 42 dished and is equipped with an annular, axially extendingrelief 43 in its outer circumferential wall communicating with the spacebetween pistons 33 and 41 by means of an inclined passageway 44. Sealingbetween cylinder 31 and piston 41 is accomplished by suitable rings 45received in a pair of axially spaced, circumferential grooves straddlingrelief 43. Finally, the wall of cylinder 31 is bored between end cap 32and piston 41 and provided with a suitable gas charging valve 46. Beforeuse, plugs 40 are removed and the space between pistons 33 and 41 filledthrough passage 39 with a non-compressible fluid, such as heavy oil.Plugs are then replaced.

The application of the present invention to a gyratory type of crusher,as illustrated in FIGURE 2, is straight forward. The customary hydraulicjack assembly may be simply omitted and in its place in the lower hubbetween end cap 51 and the lower end of the main shaft 52 of thegyratory crushing mantle 53 is substituted a suitable gas hydraulicspring 30 according to the present invention. A suitable gas, such asnitrogen, is then introduced through valve 46, forcing piston 33 againstend plug 36, until the pressure in cylinder is equal to the design loadof the crusher. End cap 32 thereof thus bears against the lower end ofshaft 52 and a snub bolt 54 is threaded up through end cap 51 to bearagainst the outer end of piston rod 34. Adjustment of snub bolt 54 willvary the spacing between mantle 53 and bowl 55 thereabove, inasmuch asshaft 52 is vertically movable in its bearings 56 relative thereto.

In the case of the cone type crusher, as illustrated in FIGURE 3,vertical adjustment of the spacing between the crushing bowl 60 and theeccentrically mounted crushing cone 61 is achieved by threadedengagement between the outer periphery of the former and annular seat62. The outer periphery of the latter in turn has spaced at intervalsthereabout a number of outwardly extending lugs 63 which seat uponcorresponding lugs 64 therebelow extending outwardly from frame 65. Apair of spaced, vertical tie bolts 66 pass slidably through each pair'of lugs 63 and 64 and have secured thereto between their lower ends ahorizontal platform base 67. Between each pair of tie bolts 66 a gashydraulic spring 30 according to the present invnetion is interposedbetween the lower face of each lug 64 and the upper face of thecorresponding platform base 67 therebelow, the ends of each piston rod34 butting against a snub bolt 68 threaded up through platform base 67.Springs 30 are pressurized so that the sum of the forces on each piston41, and thus on piston rods 34, is equal to the design load of thecrusher. Accordingly, an overload is transmitted by bowl 60 to its seat62, then to tie rods 66 and platform base 67, and finally to lugs 64 onframes through springs 30, compressing the gas therein. Any adjustmentof bowl 60 relative to cone 61 can be compensated for by turning snubbolts 68 in or out, as the case may be.

While the present invention has been described with reference toparticular embodiments and applications thereof and detailed descriptivelanguage has been used, it is not so limited. Indeed, the invention isalso adaptable to other forms of crushers, one such additionaladaptation, that to a roll type crusher, being described and claimed inapplication Ser. No. 444,919, filed March 22, 1965, a continuation ofthe aforesaid application Ser. No. 220,697. Accordingly, the followingclaims are to be read as encompassing all modifications and adaptationsof the invention falling within the spirit and scope thereof.

I claim:

1. In material crushers including a pair of spaced crushing elementshaving crushing surfaces and adapted by movement of said elementsrelative to each other to crush material therebetween, at least one ofsaid elements being movable with respect to the other in order to adjustthe spacing between said crushing surfaces, the combination therewith ofone or more gas hydraulic means operatively associated with said one ofsaid elements for maintaining a predetermined spacing between saidsurfaces during their crushing operation up to a predetermined loadtherebetween and to accommodate an overload by resiliently increasingthe spacing between said surfaces, said means comprising at least onepiston housing having opposite closed ends, a main piston in saidhousing slidable between said ends, and a gaseous fluid under pressurebetween said piston and one of said closed ends, said means beingoperatively associated with said elements so that thrust between saidsurfaces is received against the pressure of said fluid, said pressurebeing such that the total force exerted thereby is sufficient tomaintain said predetermined spacing between said surfaces up to saidpredetermined load, each of said means being self-contained andremovable from said crusher without need first to discharge any of saidfluid therefrom, and means for adjusting the spacing between saidelements, said adjusting means being effective independently of saidfluid in said housing.

2. The device of claim 1 wherein said housing is provided with afloating piston interposed for slidable movement therein between saidfirst named closed end and said main piston, said gaseous fluid beingdisposed between said first named closed end and said floating pistonand a lubricating, substantially noncompressible fluid between said mainand floating pistons.

3. The device of claim 1 wherein said main piston is provided with apiston rod extending from said housing through the other of said closedhousing ends, said gaseous fluid being disposed between said main pistonand said first named closed end of said housing, whereby said means hasa maximum over-all length.

4. The device of claim 2 wherein said floating piston is provided with aperipheral, axially extending recess in its outer longitudial surface inorder to form with the inner surface of said housing alubricant-containing chamber, said floating piston having a passage fromsaid chamber to the lubricant containing space between said pistons.

5. In a crusher of the gyratory type having a frame, a crushing bowlmounted rigidly to said frame having a downwardly opening inner crushingsurface, and a crushing mantle therebelow having a generally verticalmainshaft journaled in said frame above and below said mantle and anupwardly facing outer crushing surface operatively spaced from said bowlsurface and adapted to crush material thereagainst by gyratory movementof the lower journal of said shaft, the spacing between said surfacesbeing adjustable by vertical movernent of said mantle and shaft relativeto said bowl and frame, the combination therewith of self-contained gashydraulic means both to adjust the spacing between surfaces and tomaintain a predetermined spacing therebetween up to a predetermined loadtherebetween and to accommodate an overload by resiliently increasingsaid spacing, said means including at least one piston housing havingclosed opposite ends, a main piston in said housing slidable betweensaid ends, and a gaseous fluid under pressure between said piston and.one of said closed ends of said housing, said means being operativelyassociated with said frame and shaft so that thrust between saidcnushing surfaces is communicated to said housing and piston against thepressure of said fluid, said pressure being such that the total forceexerted thereby is suflicient to maintain said predetermined spacingbetween said bowl and mantle as long as the crushing load therebetweendoes not exceed said predetermined load, said means being removable fromsaid crusher without need first to discharge any of said fluidtherefrom, and means for adjusting the spacing between said bowl andmantle, said adjusting means being effective independently of said fluidin said housing.

6. The device of claim 5 wherein said means is interposed between saidframe and the lower end of said shaft to act substantially axially ofthe latter, and said piston is provided with a piston rod extending fromsaid housing through the other of said housing ends, said fluid beinglocated between said piston and said first named closed end of saidhousing, whereby said spring means has a maximum overall length, saidadjusting means being operative against one end of said spring means toprovide vertical adjusting movement of said shaft and mantle relative tosaid bowl and frame.

7. The device of claim 6 wherein said housing is provided with afloating piston interposed for slidable movement therein between saidfirst named closed housing end and said main piston, said gaseous fluidbeing disposed between said first named closed housing end and saidfloating piston and a lubricating, noncompressible fluid between saidmain and floating pistons.

8. The device of claim 7 wherein said floating piston is provided with aperipheral, axially extending recess in its outer wall in order to formwith the inner wall of said housing a lubricant containing chamber, saidfloating piston having a passage from said chamber to the lubricantcontaining space between said pistons.

9. In a crusher of the cone type having a frame, a crushing bowl mountedto said frame having a downwardly opening inner crushing surface, and acrushing cone therebelow having an upwardly facing outer crushingsurface operatively spaced within and from said cone surface and adaptedto crush material thereagainst by eccentric movement of the axis of saidcone relative to the axis of said bowl, the spacing between said coneand bowl being adjustable by vertical axial movement of said bowlrelative to said frame and cone, the combination therewith of means tomaintain a predetermined spacing between said surfaces up to apredetermined load therebetween and to accommodate an overload byresiliently increasing said spacing, said means including a plurality ofself-contained gas hydraulic cylinders, each of said cylinders havingopposite closed ends, a main piston in said cylinder slidable betweensaid ends having a piston rod connected thereto and extending beyondsaid cylinder through one of said ends, and a gaseous fluid underpressure between said piston and one of said closed cylinder ends, saidmeans being spaced about the outer surface of said bowl and operativelyconnected to said bowl and frame so that the crushing load is receivedagainst the pressure of said fluid, said pressure being such that thesum of the forces exerted thereby is suflicient to maintain saidpredetermined spacing between said cone and bowl as long as the loadtherebetween does not exceed said predetermined load, each of said meansbeing removable from said crusher without need first to discharge any ofsaid fluid therefrom, there being no fluid connection between any ofsaid cylinders, and means for adjusting the spacing between said coneand bowl, said adjusting means being effective independently of saidfluid in said cylinders.

110. The device of claim 9 wherein said cylinder is provided with afloating piston interposed for slidable movement therein between saidmain piston and the closed end of said cylinder remote from that throughwhich said piston rod extends, said gaseous fluid being disposed between said last-named closed end and said floating piston and alubricating, noncompressible fluid between said main and floatingpistons, whereby said means has a maximum over-all length.

11. The device of claim 10 wherein said floating piston is provided witha circumferential, axially extending recess in its outer wall in orderto form with the inner wall of said cylinder a lubricant containingannulus, said floating piston having a passage from said annulus to thelubricant containing space between said pistons.

References Cited by the Examiner UNITED STATES PATENTS 2,021,895 11/1935Newhouse 241-211 X 2,667,309 1/1954 Becker 241231 X 2,680,571 6/1954Bjarme 241215 X 2,856,035 10/1958 Rohacs.

2,873,763 2/1959 Mercier 92-182 X 2,925,959 2/1960 Werner 241290 X3,019,009 1/1962 Reifurth 267-64 3,099,406 7/1963 Kautz 241-32 ROBERT C.RIORDON, Primary Examiner. D. KELLY, Assistant Examiner.

5. IN A CRUSHER OF THE GYRATORY TYPE HAVING A FRAME, A CRUSHING BOWLMOUNTED RIGIDLY TO SAID FRAME HAVING A DOWNWARDLY OPENING INNER CRUSHINGSURFACE, AND A CRUSHING MANTLE THEREBELOW HAVING A GENERALLY VERTICALMAINSHAFT JOURNALED IN SAID FRAME ABOVE AND BELOW SAID MANTLE AND ANUPWARDLY FACING OUTER CRUSHING SURFACE OPERATIVELY SPACED FROM SAID BOWLSURFACE AND ADAPTED TO CRUSH MATERIAL THEREAGAINST BY GYRATORY MOVEMENTOF THE LOWER JOURNAL OF SAID SHAFT, THE SPACING BETWEEN SAID SURFACESBEING ADJUSTABLE BY VERTICAL MOVEMENT OF SAID MANTLE AND SHAFT RELATIVETO SAID BOWL AND FRAME, THE COMBINATION THEREWITH OF SELF-CONTAINED GASHYDRAULIC MEANS BOTH TO ADJUST THE SPACING BETWEEN SURFACES AND TOMAINTAIN A PREDETERMINED SPACING THEREBETWEEN UP TO A PREDETERMINED LOADTHEREBETWEEN AND TO ACCOMMODATE AN OVERLOAD BY RESILIENTLY INCREASINGSAID SPACING, SAID MEANS INCLUDING AT LEAST ONE PISTON HOUSING HAVINGCLOSED OPPOSITE ENDS, A MAIN PISTON IN SAID HOUSING SLIDABLE BETWEENSAID ENDS, AND A GASEOUS FLUID UNDER PRESSURE BETWEEN SAID PISTON ANDONE OF SAID CLOSED ENDS OF SAID HOUSING, SAID MEANS BEING OPERATIVELYASSOCIATED WITH SAID FRAME AND SHAFT SO THAT THRUST BETWEEN SAIDCRUSHING SURFACES IS COMMUNICATED TO SAID HOUSING AND PISTON AGAINST THEPRESSURE OF SAID FLUID, SAID PRESSURE BEING SUCH THAT THE TOTAL FORCEEXERTED THEREBY IS SUFFICIENT TO MAINTAIN SAID PREDETERMINED SPACINGBETWEEN SAID BOWL AND MANTLE AS LONG AS THE CRUSHING LOAD THEREBETWEENDOES NOT EXCEED SAID PREDETERMINED LOAD, SAID MEANS BEING REMOVABLE FROMSAID CRUSHER WITHOUT NEED FIRST TO DISCHARGE ANY OF SAID FLUIDTHEREFROM, AND MEANS FOR ADJUSTING THE SPACING BETWEEN SAID BOWL ANDMANTLE, SAID ADJUSTING MEANS BEING EFFECTIVE INDEPENDENTLY OF SAID FLUIDIN SAID HOUSING.